On a gloomy recent morning in West Oakland, tenants at the David Gray Building — or, Off-Ramp Studios, as everyone who lives there calls it — stood in the hallways outside their lofts. They gathered around their doors in nervous clusters and spoke in hushed tones, wondering aloud whether they should head to work or stay and observe while two Oakland police officers, two building services code enforcers, a fire inspector, and three property management representatives entered all of their units one by one.

Traditionally the entire procedure would have required a search warrant. But on this day, the group of cops and city officials were operating under a little-known Oakland city program, called “SMART” — Specialized Multi-Agency Response Team — that some legal experts say may be unconstitutional. That’s because they enter people’s homes without consent or a warrant.